This study is directed at examining the biosynthesis post-translational processing and biological activity of peptide hormones in the gut as they interact to regulate gastric acid secretion. The focus of this protocol will be to explore the molecular biology of the enzymes carbonic anhydrase and H(+)K(+)-ATPase, as well as the hormones gastrin and somatostatin. We propose to utilize the GCRC computer to assist us with gene sequence analysis for comparison with other biological substances.